checkpatch: ensure we do not collapse bracketed sections into constants

When determining if a return () sequence is a function style bracketing we
simplify the expression one bracket at a time replacing each with a
constant.  However this can trigger a false merge with expressions as
below:

	return (foo)0;

Prevent this false merging.

Reported-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 32d6a236570d..8d010ac0efe1 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2183,15 +2183,16 @@ sub process {
                         my $value = $2;
 
                         # Flatten any parentheses
-                        $value =~ s/\)\(/\) \(/g;
+                        $value =~ s/\(/ \(/g;
+                        $value =~ s/\)/\) /g;
                         while ($value =~ s/\[[^\{\}]*\]/1/ ||
                                $value !~ /(?:$Ident|-?$Constant)\s*
                                              $Compare\s*
                                              (?:$Ident|-?$Constant)/x &&
                                $value =~ s/\([^\(\)]*\)/1/) {
                         }
-
-                        if ($value =~ /^(?:$Ident|-?$Constant)$/) {
+#print "value<$value>\n";
+                        if ($value =~ /^\s*(?:$Ident|-?$Constant)\s*$/) {
                                 ERROR("return is not a function, parentheses are not required\n" . $herecurr);
 
                         } elsif ($spacing !~ /\s+/) {